1. 為什么導致差異Identify the Cause of the Variance

In the real world (and in examination questions) there may be other causes. The first stage in using variances to evaluate performance is to understand what caused them.

Having identified the cause of a particular variance, it is worth identifying whether other variances were also affected.

當確認一項變動時，要注意是否有其他的變動也受到影響。

For example:

Ø  A favourable materials price variance may have been caused by buying cheaper materials, but this may also have resulted in an adverse materials usage variance.

Ø  It would be meaningless therefore to say that the favourable price variance was "good" and that the adverse usage variance was "bad".

All variances that have been caused by a common factor should be considered together. It may be worthwhile to add the variances together (treating favourable variances as positive and adverse variances as negative) to appreciate the total financial impact.

每個事項的變動因素都要綜合考慮，不能只按單項的變動來確認“好”或者“壞”。

2. 誰負責 Identify Who Is Responsible

It may be that variances are being used to assess the performance of a particular manager (e.g. a factory manager).

對于變動的管理，需選取專人負責相應項目的變動確認。

Managers should only be judged on variances that are within their control. Variances are normally the responsibility of the following departments and their managers:

Ø  材料價格差異 - 生產部門或者購買部門

Materials price variance—the purchase department. However, look for signs that the purchase department may have been put under pressure to buy from a particular supplier. Or, if the purchase was requisitioned at very short notice, the purchasing department may have been unable to obtain a favourable price that it might have had otherwise.

Ø  工資率差異 – 人力資源部門、工廠經理等

Labour rate variances—this depends on who makes the decisions about how much to pay particular workers. It could be the human resources department or the factory manager.

Ø  勞動效率差異 - 工廠經理等

Labour efficiency variances are normally assumed to be the responsibility of the person who supervises the workers—this could again be the factory manager. However, these variances may also be related to the rate variance—a higher grade of labour will generally lead to an adverse rate variance, but the labourers might work more efficiently.

Ø  材料用量差異 - 生產經理或者購買經理

Material usage variances are also associated with a production manager. However, variances may also have been caused by the purchase manager buying a quality of material different from the standard.

Ø  混合和產量差異 - 生產經理或者購買經理

Mix and yield variances are normally considered to be under the control of the production manager who supervises the production process. However, these may also be affected by the quality of materials used, which could be the responsibility of the purchasing manager.

Ø  間接費用差異 – 維修經理等

Overhead variances will be the responsibility of the appropriate managers — equipment maintenance expenditure, for example, would depend on the maintenance manager.